1. Field of the Invention
The invention is directed to an ink printer means for multi-color printing of a recording medium.
2. Description of the Prior Art
As known, individual ink droplets are sprayed from one or more nozzles of an ink printer head against a recording medium for representing characters or graphics patterns. Such ink printer means are disclosed, for example, by European Pat. No. 01 59 402.
A frequent requirement for the practical employment of ink printer means is that the characters be represented with various, differing print quality. A distinction is made between what is referred to as draft quality, a standard quality and what is referred to as letter quality. The latter is also frequently referred to by the expression "near-letter-quality". For achieving various print qualities, it is known (German Published application No. 33 07 196) to vary the printing speed, i.e. to double the printing speed in comparison to the printing speed provided for the representation of characters in a standard quality and to thereby eject an ink droplet in only every second column of the matrix. It is also known from the cited European patent application No. 01 59 402 to vary the droplet volume of the ejected ink droplets dependent on the selected print quality.
Ink printer means are known both for printing in black-and-white as well as for multi-color printing. Such an ink printer means for multi-color printing of a recording medium is disclosed, for example, by European Pat. No. 00 21 389. A respectively prescribed plurality of nozzles of the ink printer head is supplied with ink of the same color. The inks are contained in ink reservoirs that are arranged perpendicular to the recording medium in succession at the backside of the ink printer head. The recording medium is printed in line-by-line fashion in a printing station and is shifted by a respective subline between two printing events, the width of this sub-line corresponding to the plurality of nozzles having ink of the same color that are arranged in proximity above one another. Such ink printer heads for color printing have a plurality of individual nozzles, for example 24 individual nozzles per head, that are arranged in six rows of four nozzles each. Three rows of the nozzles serve for the black-and-white representation and three rows serve for the color representation. One row thereby prints magenta red, another yellow and another row prints the color cyan blue.